Turbulence measurement by the pulse luminescence method using a nitrogen pulse laser

Area of Science:

• Fluid Dynamics
• Optical Measurement Techniques
• Turbulence Research

Background:

• Accurate measurement of turbulent flow velocity distribution and diffusion is crucial in fluid dynamics.
• Existing methods for turbulence analysis can be complex and time-consuming.
• Visualization of turbulent flow patterns aids in understanding complex fluid behaviors.

Purpose of the Study:

• To investigate the pulse luminescence method for visualizing and measuring turbulent flow.
• To develop an apparatus for easier and more accurate measurement of turbulence intensity.
• To confirm the fidelity of luminescent particles as indicators of fluid velocity.

Main Methods:

• Utilized a nitrogen pulse laser for instantaneous, high-power excitation.
• Employed a night vision scope, TV camera, and video tape recorder for image acquisition.
• Applied Taylor's diffusion theory to analyze turbulent diffusion patterns.
• Determined the optimal concentration of LC-G1A luminescent particles (0.05% wt).

Main Results:

• Successfully visualized turbulent flow velocity distribution and diffusion patterns.
• Quantitatively measured turbulence intensity from diffusion patterns.
• Confirmed the high fidelity of LC-G1A particles in indicating fluid velocity.
• Demonstrated the effectiveness of the pulse luminescence method for turbulence analysis.

Conclusions:

• The pulse luminescence method provides an effective means to visualize and measure turbulent flow characteristics.
• The developed apparatus and methodology allow for quantitative assessment of turbulence intensity.
• Luminescent particles are reliable tracers for fluid velocity measurements in turbulent flows.